Inkjet printers fire droplets of ink from the nozzles of a printhead assembly onto print media. The ink is provided to the printhead assembly from an ink supply. Generally, the pressure in the ink supply should be managed to control ink flow to the printhead assembly. For example, if the ink supply lacks a sufficient backpressure, ink may leak from the nozzles. Alternatively, if the backpressure in the ink supply is excessive, the nozzles may not fire properly. However, even with effective management of the backpressure, gas may accumulate in the printhead assembly. This accumulation may restrict the ability of the printhead assembly to receive ink and to deliver ink to media, thereby reducing print quality and the useful lifespan of the printhead assembly.